Dike or breakwater



(No Model.) 2 Sheets-Sheet 1. L. M. HAUPT.

DIKE 0R BREAKWATBR.

No. 880,569. Paten tedApr. 3, 1888.

(No Model.) 2 Sheets-Sheet 2. L. M. HAUPT.

DIKB 0R BRBAKWATBR.

Patented Apr. 3,1888.

FIG H UNITED STATES ATENT tries.

LEWIS M. HAUPT, OF PHILADELPHIA, PENNSYLVANIA.

DIKE. OR BREAKWATER.

SPECIFICATION forming part of Letters Patent No. 380,569, dated April 3, 1888.

Application filed December 13, 1887. Serial No. 257,810.

To all whom it may concern:

Be it known that I, LEWIS M. HAUPT, of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented a new and useful Improvement in Bikes and Breakwaters, which improvement is fully set forth in the following specification.

My invent-ion consists in certain modifications in the form, position, and arrangement of dikes and breakwaters for improving the channels of rivers and harbors, whereby the efficiency of such structures is very greatlyincreased and their injurious effects largely avoided.

That the applications of my methods may be better understood it becomes necessary to state that the resources of the profession, as at present known and practiced, are limited for harbors to dredging alone or the use of tidal scour between jetties, aided, if necessary, by dredging, and for rivers by artificially dredging the shoal spots, or by increasing the power of the current at these points by contracting the channel or by concentrating a larger volume of water where they occur, so that by its scouring action the obstructions may be washed away. Hence mechanical dredging and scour produced by current concentration between jetties constitute the sum and substance of present methods. This concentration is usually effected by one or more dikes, wing-dams, or trailing walls resting upon one or both banks of a stream or harbor-entrance, and so adjusted as to reduce the sectional area to such an extent as to produce the required velocity. For cutting a channel across the exterior bar at harbor-entrances the j etties are generally built in pairs and are made convergent; but the effect of such works is to contract the entrance, seriously to obstruct the ingress of the flood, and to render the navigation more difficult and dangerous.

The general principles involved in the work of river and harbor improvement, and which my methods are designed to employ, arc

First. If the bottom velocity of a stream be increased to the limit required by the character of the material forming its bed, it will scour; if diminished, it will deposit.

Second. If the momentum of a stream be suddenly arrested or changed in direction by (No model.)

an obstruction placed in its path, a reaction will be produced, its head will be increased, and the bottom will be secured out. This is particularly observable under the concave banks of bonds, where the deepest water is generally found.

Third. If the volume of a stream be partially deflected by a trailing wall from one side of a cross-over bar to the opposite side, the current over the bar will be quickened and the crest will be lowered on the upstream side of the work.

Fourth. If the form of the cross-section of a stream be modified by cutting at one point and filling at another point of the same section, so that the area is not changed, (other things being equal,) the discharge will not be materially affected and the part so deepened will remain open. v

Fifth. As a stream undergoes compression Seventh. While the plane of tidal scour should be lowered,-there should be no general disturbance of the entire bodyofthe bar, which would otherwise re-form when the velocity of the current becomes normal.

Eighth. The scouring-force of a current is proportioned to the square of the velocity, while its transporting capacity varies as the sixth power.

Ninth. Ajetty which causes an abrupt angular change in the direction of a current will produce injurious eddies and cause bars to be formed where they may become serious obstructions.

Tenth. The path of the ebb-stream in approaching and crossing the outer bar of harbors is along the line of least resistance, or at an angle of ninety degrees, or thercabout, to that of the flood resultant, where it is possible,

and the deepest water is at the point where the flood action is the weakest.

The following observations will also be found of valuein designing works for harborand river improvements:

(a) The character, direction, and relative intensities of the forces acting upon any harborentrance may be determined with considerable accuracy from a study of the submerged to pography and other local physical features.

(1)) The form of the sandy spits adjacent to the entrance and the flood-tide channel lying under one of them and the ebb under the other will, in general, indicate the direction of the resultant movement.

(a) Harbor-bars are the results of the resistance offered by the shores to the momentum of the flood-tide, and are composed almost entirely of beach sand and shingle.

(d) The flood and ebb forces are antagonistic, and the greatest effect of the one will be found where the energy of the other is least.

(6) The position of the entrance with reference to the general trend of the coast and cotidal lines will indicate generally the direction of the flood resultant and position of the ebbchannel.

In accordance with these principles and observationsIhave designed such forms of breakwaters and dikes and propose to place them in such positions as to produce the following results:

First. The operation of the natural forces in removing bars or preventing their formation is materially aided without serious interference with either the flood or ebb currents.

Second. By changing the directions of the confluent ebb -currents before reaching the gorge by interior dikes, this resultant is increased for more efficient scour on the outer bar.

Third. By utilizing the natural tendencies of the flood a beach-channel is cut under the nearerlip of the inlet, and this channel is deepened by compressing the flood into it by reaction-wings.

Fourth. The advancing flood-waveis broken up by an obstruction designed to cause it to precipitate its load of sand on the outer slope of the bar, yet not to prevent the ingress of the flood-prism, while at the same time it also prevents the dissipation of the ebb through and over the weir or swash channels, and so increases its effective action on the bar.

Fifth. Better results are secured with a development of about one-tliird to one-half of that ordinarily required, as it is possible to dispense entirely with one jetty and part of another.

Sixth. The designs proposed also reduce greatly the risks to navigation and become aids instead of dangers, as is the case with many jetties, especially when submerged.

In harbors the proper form for a breakwater to secure these desiderata is one composed of a series of intersecting arcs having their cusps or salients so placed as to cut the advancing waves and resolve them into components along the concave faces of-the structure, which is intended to extend above high water. means the opposing components in the same cove will neutralize each other and the transporting-power of the wave be destroyed, and shoals will form outside of the barrier, which will tend to re-enforce it and establish its po- 7 sition. The form preferred would be that composed of one or more curves or semi-ellipses, with a semi-conjugate axis of about one-fourth the transverse, and at the shore end having a straight or slightly curved flank extending inward toward the gorge, to produce a reaction and compression upon that part of the flood intended to scour out and maintain the beachchannel. The position would be on or near the crest of the outer bar, where it would de- 8 5 fend the ebb-channel lying behind it and conserve the ebb forces for action upon the weakest part of the bar, while at the same time it will oppose and disintegrate the flood without materially reducing the area of the section of 0 ingress. The curves may be placed with their vertices opposite to each other, forming a double funnel-shaped passage of the form of an hour-glass, through the gorge of which the tidal currents would be compressed with in- 5 creased velocity.

In tidal rivers the form would be a reverse curve or ogee placed upon or near to the bar across which a channel is desired, and so adjusted as to produce a reaction of the imping- IOO ing currents upon the bottom to create and maintain a channel. If the currents have not sufficient velocity to cut the channel, they may be aided mechanically by dredging out the out in front of and filling behind the bulkhead represents a plan of a reaction-dike at the upstream end of Pettys Island in the'Delaware River, New Jersey.

Referring to Fig. I, the direction of the advancing flood resultant outside the bar and during the first and second quarters is shown :25

at A. During the remaining-half of the flood, and after the front of the wave has passed, it swings around to a direction nearly normal to the inlet. The flood-channel is seen in Maffits channel under Sullivans Island. The sev- 13o eral swash-channels cross the bar at intervals, and the main ship-channel is at the point of the bar farthest removed from the entrance. The ebb thalweg lies nearly at right angles to By this 70 Fig. II 1 :5

the flood movement, and is in part defended by the submerged bar built by the flood. B B B are the groins of the proposed breakwater, built in the form of semi-ellipses, or any other curves which shall decompose and neutralize the flood energy. B F is the reaction flank, intended to compress the flood in its passage through the shore or flood channel. U S J and a 5 are the submerged jetties in process of construction at this entrance, and which are so placed as to attempt to force the ebb to discharge in the face of the flood, and which require amuch greater length of development. G D and E G, Fig. I, represent an arrangement of curves with their vertices opposite each other, whereby the tidal currents are compressed and increased in velocity over the crest of the bar.

In Fig. II, B B indicate the are or curved portion of the breakwater, and B F the reaction-flank. The breakwater is placed as in Fig. I, so as to decompose and neutralize the flood energy and compress the flood on its passage through the shorechannel. R D represent the reaction-dike, in the form of a reverse curve, springing from Pelican Island, and co-opcrating with the breakwater by conserving the energy of the inner forces for ebb effects. The broken line U S Jrepresents the position of the submerged Government jetties at this point, the effect of which has been to move the bar bodily seaward, which effect it was desired to avoid. The drawing indicates the topography at two dates-to wit, 1850 and 1867for the shoreline, illustrating the movement and showing the direction and extent of the erosion in these seventeen years. The outer bar (1883) shows the effect of the submerged jetty at this latter date.

In Fig; III is illustrated a reaction-dike, R D, at the upstream end of Pettys Island in the Delaware River. The form of the dike is a reverse curve, as shown, designed to withdraw a part of the ebb-discharge from the south and throw itinto the north channel, and so scour off the lower extremity of Five Mile Bar and make a channel for navigation, thus securing by one short (like what has generally required one or two of considerably greater length. Moreover, the action is local and direct and the dike is a guide and aid to navigation, whereas in methods hitherto adopted the action is general and the position of the deeper water is not well defined. The direction of the ebb is indicated by the arrow.

I am aware that curved dikes have been proposed for such improvements; but they are not of such form as will secure the results required for a successful treatment of the forces they are designed to control, nor are they properly placed, and I do not claim any originality in a simple curve as applied to the plan of a dike or breakwater; but

What I do claim, and desire to secure by Letters Patent, is-

1.. A breakwater or dike rising to or about the water-level, composed of a combination of curves so arranged as to resist and decompose the flood resultant over aportion of the outer bar;'and at the same time to permit the free ingress of the tidal prison to the inner basin, substantially as described.

2. A breakwater rising to or about the water-level and composed of a combination of curves and right lines"so arranged as to resist and decompose the flood resultant over aportion of the outer bar, and at the same time to permit the free ingress of the tidal prism to the inner basin, substantially as described.

3. The breakwater herein described, rising to or about high water and consisting of a con cave curved portion and a flank angularly approaching but disconnected from the shore, to produce a reaction and compression upon that part of the flood intended to scour out and maintain the beach-channel, substantially as set forth.

4. A breakwater rising to or about highwater level and comprising one or more curves having their cusps or salients placed so as to cut the advancing waves and resolve them into components along the concave faces of the structure, substantially as described.

5. A breakwater rising to or about highwater level and for improving the channels of rivers and harbors, said break water consisting of one or more semi-ellipses having at the shore end astraight or approXimately-strai ght flank, substantially as described.

6. A dike for improving channels, said dike being composed of curves concave toward the current so disposed as to withdraw a part of the current from one channel and divert it into another, substantially as described.

7. A reaction-dike in tidal waters, composed of curves concave toward the current and disconnected from the main shore-lines, and so disposed as to divert part of the current force from one channel into another, substantially as described.

8. The combination of the breakwater composed of a series of intersecting arcs and a straight or slightly-curved flank, and the dike composed of compound or reverse curves for conserving the energy of the inner forces, substantially as described.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

LEWIS M. HAUPT.

lVit-nesses:

CHARLES W. SPARHAWK, ROBERT W. DAVIS.- 

